2 * handle transition of Linux booting another kernel
3 * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com>
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
10 #include <linux/kexec.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/numa.h>
14 #include <linux/ftrace.h>
16 #include <asm/pgtable.h>
17 #include <asm/pgalloc.h>
18 #include <asm/tlbflush.h>
19 #include <asm/mmu_context.h>
22 #include <asm/cpufeature.h>
24 #include <asm/system.h>
25 #include <asm/cacheflush.h>
27 #define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
28 static u32 kexec_pgd
[1024] PAGE_ALIGNED
;
30 static u32 kexec_pmd0
[1024] PAGE_ALIGNED
;
31 static u32 kexec_pmd1
[1024] PAGE_ALIGNED
;
33 static u32 kexec_pte0
[1024] PAGE_ALIGNED
;
34 static u32 kexec_pte1
[1024] PAGE_ALIGNED
;
36 static void set_idt(void *newidt
, __u16 limit
)
38 struct desc_ptr curidt
;
40 /* ia32 supports unaliged loads & stores */
42 curidt
.address
= (unsigned long)newidt
;
48 static void set_gdt(void *newgdt
, __u16 limit
)
50 struct desc_ptr curgdt
;
52 /* ia32 supports unaligned loads & stores */
54 curgdt
.address
= (unsigned long)newgdt
;
59 static void load_segments(void)
62 #define STR(X) __STR(X)
64 __asm__
__volatile__ (
65 "\tljmp $"STR(__KERNEL_CS
)",$1f\n"
67 "\tmovl $"STR(__KERNEL_DS
)",%%eax\n"
79 * A architecture hook called to validate the
80 * proposed image and prepare the control pages
81 * as needed. The pages for KEXEC_CONTROL_CODE_SIZE
82 * have been allocated, but the segments have yet
83 * been copied into the kernel.
85 * Do what every setup is needed on image and the
86 * reboot code buffer to allow us to avoid allocations
89 * Make control page executable.
91 int machine_kexec_prepare(struct kimage
*image
)
94 set_pages_x(image
->control_code_page
, 1);
99 * Undo anything leftover by machine_kexec_prepare
100 * when an image is freed.
102 void machine_kexec_cleanup(struct kimage
*image
)
105 set_pages_nx(image
->control_code_page
, 1);
109 * Do not allocate memory (or fail in any way) in machine_kexec().
110 * We are past the point of no return, committed to rebooting now.
112 void machine_kexec(struct kimage
*image
)
114 unsigned long page_list
[PAGES_NR
];
116 asmlinkage
unsigned long
117 (*relocate_kernel_ptr
)(unsigned long indirection_page
,
118 unsigned long control_page
,
119 unsigned long start_address
,
120 unsigned int has_pae
,
121 unsigned int preserve_context
);
125 /* Interrupts aren't acceptable while we reboot */
128 control_page
= page_address(image
->control_code_page
);
129 memcpy(control_page
, relocate_kernel
, PAGE_SIZE
/2);
131 relocate_kernel_ptr
= control_page
;
132 page_list
[PA_CONTROL_PAGE
] = __pa(control_page
);
133 page_list
[VA_CONTROL_PAGE
] = (unsigned long)control_page
;
134 page_list
[PA_PGD
] = __pa(kexec_pgd
);
135 page_list
[VA_PGD
] = (unsigned long)kexec_pgd
;
136 #ifdef CONFIG_X86_PAE
137 page_list
[PA_PMD_0
] = __pa(kexec_pmd0
);
138 page_list
[VA_PMD_0
] = (unsigned long)kexec_pmd0
;
139 page_list
[PA_PMD_1
] = __pa(kexec_pmd1
);
140 page_list
[VA_PMD_1
] = (unsigned long)kexec_pmd1
;
142 page_list
[PA_PTE_0
] = __pa(kexec_pte0
);
143 page_list
[VA_PTE_0
] = (unsigned long)kexec_pte0
;
144 page_list
[PA_PTE_1
] = __pa(kexec_pte1
);
145 page_list
[VA_PTE_1
] = (unsigned long)kexec_pte1
;
146 page_list
[PA_SWAP_PAGE
] = (page_to_pfn(image
->swap_page
) << PAGE_SHIFT
);
148 /* The segment registers are funny things, they have both a
149 * visible and an invisible part. Whenever the visible part is
150 * set to a specific selector, the invisible part is loaded
151 * with from a table in memory. At no other time is the
152 * descriptor table in memory accessed.
154 * I take advantage of this here by force loading the
155 * segments, before I zap the gdt with an invalid value.
158 /* The gdt & idt are now invalid.
159 * If you want to load them you must set up your own idt & gdt.
161 set_gdt(phys_to_virt(0),0);
162 set_idt(phys_to_virt(0),0);
165 image
->start
= relocate_kernel_ptr((unsigned long)image
->head
,
166 (unsigned long)page_list
,
167 image
->start
, cpu_has_pae
,
168 image
->preserve_context
);
171 void arch_crash_save_vmcoreinfo(void)
174 VMCOREINFO_SYMBOL(node_data
);
175 VMCOREINFO_LENGTH(node_data
, MAX_NUMNODES
);
177 #ifdef CONFIG_X86_PAE
178 VMCOREINFO_CONFIG(X86_PAE
);